Enable Job-Token authentication in GitLab Core

What does this MR do?

Given Job-Token authentication itself is not allowed for any endpoints by default (in other word, we need to explicitly specify which endpoint can accept the job-token header), we can safely move the #find_user_from_job_token into core level. This fixes the above problems on Job Artifact API and Release API.

We should also fix the doc as it's misleading that we don't allow Job-Token in any API even if user has EEP license.

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• [-] Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team

Closes #37898 (closed)